And you have of course verified that your PIC is actually working, you've got volts where you should have them, and you've programmed it for the correct Oscillator and MCLR usage?

Here's an example of PBP code that works for you to compare in case you've missed anything in the PICs initialisation... btw... it's a good idea to use TRISIO to configure your PICs pin I/O before you use it.

http://www.picbasic.co.uk/forum/showthread.php?t=3510